1. Field of the Invention:
This invention relates to a method of joining a cast iron member to another member of cast iron or other metal.
2. Description of the Prior Arts:
Cast iron is widely used in various fields of industry, and particularly, for industrial machines and internal combustion engines, since it is inexpensive, and has excellent mouldability and vibration damping properties. There are, however, considerable limitations to the use of cast iron in fabricated structures since it is not easy to join two cast iron members or a cast iron member and a member of other metal by brazing, welding or fusing.
For example, the top of a cast aluminium alloy piston for a diesel engine is required to be heat and wear resistant in order to resist an increased thermal load. It has, therefore, been proposed to join cast iron or a ceramic material to the top of the piston by fusing, caulking or bolting or otherwise. The combination of such different materials is, however, still far from satisfactory from the standpoint of reliability and economy. For example, the piston is liable to crack as a result of rapid heating for casting or insufficient fusion, or to be damaged by vibration upon exposure to a high temperature during the operation of the engine.